we are using AutoCad mechanical 2010.
from one our consultants, we recieved some file which was drawn by AutoCad Civil 2010.
now a strange thing is happening; when we open the drawing made by Civil 2010 in Mechanical 2010, it opens properly. BUT after making some changes when we save it. next time it wont show the full contents of the file. means some of the drawing lines (almost 60%) is missing.